Israel is another candidate, given that Israel has beef with Spain for Spanish government not supporting/approving the genocide in Gaza.
Evidence is not easy to find on these topics. It's espionage for christ's sake. You need to analyze material incentives and be familiar with the methods used. You cannot expect the media to hand you the answers, because that is not the purpose of the media especially on topics like this.
Israel responds to words with words. They respond to force with force. And they are busy enough dealing with the trouble that Iran keeps stirring up, they're not going to do anything to Spain. (Not to say that it would be out of the question for them to go after terrorists who were in Spain, but it would be very focused. Look at what happened after Munich--multiple European countries were incredibly inept about extraditing the attackers so Israel responded with assassination teams. Not strikes on anything they didn't believe had hurt them.)
(And there never was a genocide, but this isn't the thread for it.)